La Niña persists

The year started with La Niña conditions over the Pacific Ocean. Unseasonable cold at the start of January (Special Climate Statement 36) kept January average maximum temperatures close to normal in the northeast but average daytime temperatures in parts of the south and west were above average (and again in February). One notable exception was Mt Hotham which set a new lowest January maximum temperature record for Australia, averaging only 0.6 °C. The wettest single day was 10 February when Pennyroyal Creek recorded 223.0 mm.
Rainfall for January and February was below average in the west but above average in the centre/north. At the end of February, severe thunderstorms and heavy rainfall broke many highest daily rainfall records in the State's northeast. Night-time temperatures in January and February were above average in most parts and very much above average in the southwest. The warmest night for 2012 was 26.3 °C, shared by Cape Otway Lighthouse on 26 February and Yarrawonga on 30 November.

La Niña decays

By the beginning of autumn the La Niña was nearing its end but its presence was still being felt with Victoria recording its third-wettest March with more than double the normal total. While rainfall for April and May was generally average to below average, autumn totals were above average in the east and close to normal in the west. Daytime temperatures for autumn were above average in the southwest but below average in parts of the north and east. Night-time temperatures were above average in the south and below average in the north.

Close to El Niño

Winter began with neutral conditions in the Indian and Pacific oceans but climate models indicated warming in both oceans was likely during the coming months. Rainfall for winter was above average in the south but below average in parts of the north. Daytime temperatures for winter were close to normal in most parts. The coldest day of the year was 31 August when Mount Hotham only reached –4.5 °C. Night-time temperatures in winter were above average in parts of the south and below average in parts of the north. The coldest night was 6 July when Mount Hotham dropped to –8.0 °C.

Still Close to El Niño

Spring started with sea surface temperatures in the Pacific Ocean still at near El Niño thresholds. Rainfall totals for spring were below average to very much below average across most of the State (spring 2012 ranks as the 10th driest on record). Daytime temperatures for spring were above average to very much above average, November 2012 was Victoria's sixth-warmest on record and spring 2012 ranks as the eighth-warmest. The hottest day of the year was 29 November when Ouyen (Post Office) recorded 45.8 °C (a new spring record for Victoria, many other stations set records that day). Night-time temperatures in spring were above average in the south but close to average in the north. However the months of the season were varied with September's night-time temperatures mostly close to normal, October's below average in the north and November's above average everywhere. By the end of spring, El Niño indicators were at neutral levels and looked likely to persist for the remainder of the year.

Neutral conditions in the Pacific

During December, daytime temperatures were above average (except in the northeast) and night-time temperatures were above average in some parts of central and western of Victoria. Rainfall for December was average to below average.

Summary

Rainfall totals for 2012 across Victoria were mixed. Highlighting the variability, the wettest station overall, Mount Baw Baw, recorded 2225.6 mm whilst the driest, Walpeup Research, recorded only 159.6 mm. Parts of the east recorded above-average rainfall while parts of the west were drier than normal. Rainfall totals were close to normal in central parts. A couple of stations had their highest total rainfall on record. The warmest station on average (an average of maximum and minimum temperatures) was Mildura Airport with 17.4 °C and the coolest on average was Mount Hotham with 4.2 °C. Daytime temperatures in Victoria during 2012 were above average in the west and close to normal in the east. The warmest days on average were recorded at Mildura Airport with 24.8 °C but the warmest nights on average were recorded at Gabo Island Lighthouse with 12.4 °C. Mount Hotham recorded the coolest days on average with 7.1 °C, and the coolest nights on average with 1.2 °C. A couple of stations recorded their equal highest mean daily maximum temperature on record whilst a few others their lowest mean daily maximum temperature on record. A few stations had their lowest mean daily minimum temperature on record. There are maps of rainfall deciles, maximum temperature anomalies and minimum temperature anomalies below.

Notes

A Annual Climate Summary is prepared to list the main features of the weather in Victoria using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at
9 am on Wednesday 2 January 2013.
Some checks have been made on the data, but it is possible that results will change
as new information becomes available.

Averages are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median
is sometimes more representative than the
mean
of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site,
based on the
decile ranking
(very low rainfall is in decile 1, low in decile 2 or 3,
average in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a
percentage of the long-term mean.